1. Field of the Invention
This invention relates generally to the field of material handling, and is concerned in particular with an apparatus for assembling tubes, bars, rods and other like elongated elements preparatory to bundling the same.
2. Description of the Prior Art
Numerous arrangements have been proposed for assembling elongated elements of the type referred to above. In some of these arrangements, for example those disclosed in U.S. Pat. Nos. 4,268,203 (Huber et al); 3,950,920 (Thomsen et al); and 3,871,288 (White), the elements are accumulated in assembly zones defined by the catenaries of flexible chains, slings or the like. The difficulty with such arrangements is that as the sizes of the catenaries are gradually increased during assembly, the elongated elements in contact with the chains or slings are rolled one against the other. This in turn can lead to twisting or "jackstrawing" of the elements, a condition which is detrimental to the final bundle.
Other known arrangements, for example those disclosed in U.S. Pat. Nos. 4,174,662 (Klusmier); 3,338,376 (Cross); and 2,592,642 (Bardet) deposit elements in assembly zones defined in part by stationary members and in part by elevator platforms which are lowered gradually during assembly. The primary drawback of such arrangements is that they require overly complex and costly mechanisms for depositing or layering the elongated elements in the assembly zones.